title: Estimation of internal exposure of the thyroid to (131)I on the basis of (134)Cs accumulated in the body among evacuees of the Fukushima Daiichi Nuclear Power Station accident.
abstract: Namie Town was heavily contaminated by the Fukushima Daiichi Nuclear Power Station accident. The thyroid equivalent dose for residents who lived in Namie was estimated using results of whole body counting examinations which were carried out by the Japan Atomic Energy Agency a few months after the nuclear accident. Photon peaks of (131)I and (134)Cs were previously measured by the authors using a NaI(Tl) scintillation spectrometer and that information was used to estimate the (131)I/(134)Cs activity ratio of total intake in the present study. The maximum values of (131)I/(134)Cs activity ratio corresponding to thyroid uptake factors of 0.3, 0.1 and 0.03 were evaluated to be 0.9, 2.6 and 8.7, respectively. The maximum value of the (131)I/(134)Cs activity ratio was used to obtain the most conservative thyroid equivalent dose estimation. The maximum internal exposure of the thyroid to (131)I on the basis of (134)Cs accumulated in the body measured by the whole body counter was estimated to be 18mSv. This value was much smaller than 50mSv that the International Atomic Energy Agency recommends as the dose at which exposed persons should take stable iodine tablets.
authors.affiliation: Department of Radiological Life Sciences, Hirosaki University Graduate School of Health Sciences, 66-1 Hon-cho, Hirosaki City, Aomori 036-8564, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hosoda
authors.forename: Shinji
authors.initials: S
authors.lastname: Tokonami
authors.forename: Suminori
authors.initials: S
authors.lastname: Akiba
authors.forename: Osamu
authors.initials: O
authors.lastname: Kurihara
authors.forename: Atsuyuki
authors.initials: A
authors.lastname: Sorimachi
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ishikawa
authors.forename: Takumaro
authors.initials: T
authors.lastname: Momose
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakano
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Mariya
authors.forename: Ikuo
authors.initials: I
authors.lastname: Kashiwakura
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000396:Air Pollutants, Radioactive / Q000032:analysis*; D002587:Cesium Isotopes / Q000032:analysis*; D002648:Child; D002675:Child, Preschool; D004781:Environmental Exposure; D005260:Female; D062406:Fukushima Nuclear Accident; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007457:Iodine Radioisotopes / Q000032:analysis*; D007564:Japan; D008297:Male; D008875:Middle Aged; D013961:Thyroid Gland / Q000737:chemistry*; D014915:Whole-Body Counting; D055815:Young Adult
chemical_list: D000396:Air Pollutants, Radioactive; D002587:Cesium Isotopes; D007457:Iodine Radioisotopes
keywords: (131)I/(134)Cs activity ratio; Fukushima nuclear accident; Radioiodine; Thyroid dose assessment; Uptake factor; Whole body counting